The Side Effects of the Mark of Cain
by bbgirl189
Summary: Sam and Dean deal with a guilty Sam and what happens when Dean doesn't follow the Mark's call to kill.


_**This fanfiction has spoilers from season 10 episode 21 and ends into episode 22. So if you haven't seen this far, please don't read it. Also warning, this story does touch bases with cutting/ self harm, if this is offensive to you... Please don't read it.**_

Sam and Dean sat in their bunker's main room, each lost in their own thoughts. Everyone the boys came to care for seemed to die on them. With adding the passing of Charlie to the list of family they had lost, the rift between Sam and Dean was growing steadily larger. Dean blamed Sam for her death, and wouldn't see reason. Sam simply felt like a cursed bad omen, stuck getting everyone he loved killed.

Sam stood up after a while, deciding to go for a walk. He needed to clear his head, as well as get away from the ever watchful eye of his older brother. Since he had stopped drinking demon blood to survive, he had needed to find another way to cope with the crap that went down on an everyday basis.

No one would ever be able to guess that Sam was hurting as much as he was, he had learned how to hide it from his brother and Cas. The only one who knew how much he was truly dealing with, was Charlie. She had always tried to help him when she was around. Sam knew that if life hadn't been as screwed up as it was, Dean would have figured out his vice a long time ago. But with the Mark of Cain making Dean need to kill more than anything else, noticing his little brother's bad habit was very unlikely.

Sam walked aimlessly down the street, until he came to the local library. He smiled to himself, as he slipped inside and made a beeline for the bathroom. He closed himself into a stall and pulled out a tiny silver blade, it looked brand new except for the very tip was a rusty color from old blood. He pulled his sleeves up, revealing a bunch of tiny lined scars up and down his forearms. He held his breath as he drew the sharpened tip downward into his skin and across it, eliciting a hiss as his arm started to bleed. He smiled as he watched the blood drip a trail down his arm, it had always mesmerized him.

Suddenly his cell phone rang, causing him to jump and frantically grab at his pocket. Pulling it out, he saw he had missed a call from Dean, but he didn't care. His mind already preoccupied as he cut into his other arm, leaving a mark similar to the first arm. Sam made identical cuts on both arms until he felt better, totalling at about six cuts per arm.

Unbeknownst to Sam, Dean was back at the bunker and not doing well. He was frantically trying to find his brother as well as keep the Mark at bay. Dean finally gave in and walked outside searching for Sam, with no clue where to look. He couldn't figure out why Sam wouldn't answer his calls, so he tried calling again for the tenth time in less than an hour.

Dean was just about to call Cas to come help him when he recaived a text from Sam saying he was at the library and would be back soon. Dean sighed in relief and went back inside the bunker to lay down. He collapsed on his bed and groaned, his stomach was churning and his head was pounding.

"Damn... kid, keeps trying to disappear on me." Dean ground out, as he pushed himself up and to the bathroom. He walked up to the mirror, and paled when he saw how sickly he looked. He gagged under his breath, before vomiting into the sink in front of him. He gasped weakly pushing away from the sink and collapsing on the floor in front of the toilet, just in time to vomit again.

Sam walked in the bunker, feeling better and less tightly wound up. He had picked up burgers amd beer for his brother, as well as salad and beer for himself. He looked around in confusion, wondering where his brother was.

"Dean?" Sam called into the surprisingly empty sounding bunker. He listened advancing further into the bunker, hoping his brother hadn't gone on another killing spree.

Suddenly his phone beeped signalling a text from Dean, 'in the bathroom, need help.' Sam put everything down and ran down the hall, stopping when he got to the bathroom.

"Dean? You okay?" Sam asked, as he walked slowly into the bathroom. He saw the puked in sink first, wondering what on earth. He turned around and gasped softly when he saw Dean, leaning against the stall weakly, pale and shaking.

"Where were you? And why are you bleeding?" Dean asked roughly, his voice raw. Sam looked down and saw that he had bled through his sleeves, but acted like it was no big deal.

"Library, must've knicked myself on a book. Are you alright? What haooened? When did you start feeling sick?" Sam asked rapidly, crouching down beside Dean.

Dean grabbed Sam's arm tightly, and ripped the sleeve up to reveal the cuts. Sam paled as Dean did the same to his other arm.

"What the hell, Sammy?!" Dean gasped out, seeing how many cuts and scars were on his little brother's arms. Sam flinched as his brother called him Sammy, and panicked when he realized his secret was out.

"I didn't know what else to do. It's my fault they all died..." Sam said brokenly, feeling like the world was trying to crush him. Dean looked at his little brother in shock, and felt his brother's pockets until he found the knife he had been using.

"Sammy, its not just your fault... it's mine too... I shouldn't have blamed you... I was just pissed and never realized that you would feel like this," gesturing to the knife and Sam's arms, "was your only option... I'm so sorry..." Dean said sadly, he was mortified that his little brother would resort to cutting to escape the pain. Sam looked at his brother in surprise and shook his head, he was feeling too overwhelmed and didn't know what to do.

Dean slowly tried to stand up, only to end up vomiting again. Sam was immediately closer to him, rubbing gentle circles on his back. Dean's back tensed again, as he continued vomiting until his stomach was empty and he was left dry heaving.

"Easy... easy..." Sam said gently, trying to soothe his brother as he helped guide him to against the stall again.

"I'm alright. It's a normal side effect of the Mark." Dean gasped out, looking at Sam sadly.

"Oh, yuck." Sam said simply, grossed out but worried about how his brother had been managing the Mark this whole time with that side effect.

"Yeah, yuck is right. I'm okay now... What can I do to help you stop cutting?" Dean asked directly, as he got up and started cleaning up his mess. Sam shrugged, trying to pass it off as no big deal which caused Dean to glare at him.

"We will deal with this after I find and kill Charlie's killers." Dean spat in agitation...


End file.
